[PATCH 01/25] VFS: move attr_kill logic from notify_change into helper function

From: Jeff Layton
Date: Mon Aug 06 2007 - 09:23:02 EST


Separate the handling of the local ia_valid bitmask from the one in
attr->ia_valid. This allows us to hand off the actual handling of the
ATTR_KILL_* flags to the .setattr i_op when one is defined.

notify_change still needs to process those flags for the local ia_valid
variable, since it uses that to decide whether to return early, and to pass
a (hopefully) appropriate bitmask to fsnotify_change.

Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
---
fs/attr.c | 54 +++++++++++++++++++++++++++++++++------------------
include/linux/fs.h | 1 +
2 files changed, 36 insertions(+), 19 deletions(-)

diff --git a/fs/attr.c b/fs/attr.c
index f8dfc22..47015e0 100644
--- a/fs/attr.c
+++ b/fs/attr.c
@@ -100,15 +100,39 @@ int inode_setattr(struct inode * inode, struct iattr * attr)
}
EXPORT_SYMBOL(inode_setattr);

+void attr_kill_to_mode(struct inode *inode, struct iattr *attr)
+{
+ if (attr->ia_valid & ATTR_KILL_SUID) {
+ attr->ia_valid &= ~ATTR_KILL_SUID;
+ if (inode->i_mode & S_ISUID) {
+ if (!(attr->ia_valid & ATTR_MODE)) {
+ attr->ia_valid |= ATTR_MODE;
+ attr->ia_mode = inode->i_mode;
+ }
+ attr->ia_mode &= ~S_ISUID;
+ }
+ }
+ if (attr->ia_valid & ATTR_KILL_SGID) {
+ attr->ia_valid &= ~ATTR_KILL_SGID;
+ if ((inode->i_mode & (S_ISGID | S_IXGRP)) ==
+ (S_ISGID | S_IXGRP)) {
+ if (!(attr->ia_valid & ATTR_MODE)) {
+ attr->ia_valid |= ATTR_MODE;
+ attr->ia_mode = inode->i_mode;
+ }
+ attr->ia_mode &= ~S_ISGID;
+ }
+ }
+}
+EXPORT_SYMBOL(attr_kill_to_mode);
+
int notify_change(struct dentry * dentry, struct iattr * attr)
{
struct inode *inode = dentry->d_inode;
- mode_t mode;
int error;
struct timespec now;
unsigned int ia_valid = attr->ia_valid;

- mode = inode->i_mode;
now = current_fs_time(inode->i_sb);

attr->ia_ctime = now;
@@ -117,26 +141,17 @@ int notify_change(struct dentry * dentry, struct iattr * attr)
if (!(ia_valid & ATTR_MTIME_SET))
attr->ia_mtime = now;
if (ia_valid & ATTR_KILL_SUID) {
- attr->ia_valid &= ~ATTR_KILL_SUID;
- if (mode & S_ISUID) {
- if (!(ia_valid & ATTR_MODE)) {
- ia_valid = attr->ia_valid |= ATTR_MODE;
- attr->ia_mode = inode->i_mode;
- }
- attr->ia_mode &= ~S_ISUID;
- }
+ ia_valid &= ~ATTR_KILL_SUID;
+ if (inode->i_mode & S_ISUID)
+ ia_valid |= ATTR_MODE;
}
if (ia_valid & ATTR_KILL_SGID) {
- attr->ia_valid &= ~ ATTR_KILL_SGID;
- if ((mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) {
- if (!(ia_valid & ATTR_MODE)) {
- ia_valid = attr->ia_valid |= ATTR_MODE;
- attr->ia_mode = inode->i_mode;
- }
- attr->ia_mode &= ~S_ISGID;
- }
+ ia_valid &= ~ATTR_KILL_SGID;
+ if ((inode->i_mode & (S_ISGID | S_IXGRP)) ==
+ (S_ISGID | S_IXGRP))
+ ia_valid |= ATTR_MODE;
}
- if (!attr->ia_valid)
+ if (!ia_valid)
return 0;

if (ia_valid & ATTR_SIZE)
@@ -147,6 +162,7 @@ int notify_change(struct dentry * dentry, struct iattr * attr)
if (!error)
error = inode->i_op->setattr(dentry, attr);
} else {
+ attr_kill_to_mode(inode, attr);
error = inode_change_ok(inode, attr);
if (!error)
error = security_inode_setattr(dentry, attr);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index d33bead..f617b23 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1561,6 +1561,7 @@ extern int do_remount_sb(struct super_block *sb, int flags,
#ifdef CONFIG_BLOCK
extern sector_t bmap(struct inode *, sector_t);
#endif
+extern void attr_kill_to_mode(struct inode *inode, struct iattr *attr);
extern int notify_change(struct dentry *, struct iattr *);
extern int permission(struct inode *, int, struct nameidata *);
extern int generic_permission(struct inode *, int,
--
1.5.2.2

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